This invention relates to metal pipe forming apparatus, and in particular to a mount for the horn or mandrel in the multiple roll pipe forming head of the apparatus.
Machines for continuously manufacturing metal pipe from an elongated sheet of metal are well known. Such pipe is used for a variety of purposes, including culvert. U.S. Pat. No. 3,247,692 is directed to a spiral pipe making machine having a pipe forming head comprising three adjustable rolls, each of the rolls comprising a series of interconnected rollers.
U.S. Pat. No. 4,070,886, developed by one of the inventors of the present application, is directed to a more sophisticated but similar pipe forming machine for forming pipe from helical convolutions, where the rollers of the pipe forming device are automatically adjusted when different diameters of pipe are to be manufactured. The '886 patent include a horn or mandrel in the forming device about which the helical convolutions of metal are curled in an upward orientation. It is a horn or mandrel, such as that of the '886 patent, which is the subject matter of the present application, and U.S. Pat. No. 4,070,886 is hereby incorporated herein by reference.